Enhanced paging procedures for machine type communications (MTC)

ABSTRACT

Certain aspects of the present disclosure generally relate to wireless communications, and more specifically to enhanced paging procedures for devices with limited communications resources, such as machine type communication (MTC) devices and enhanced or evolved MTC (eMTC) devices. An example method generally includes determining a set of subframes corresponding to a paging occasion for the UE to receive a paging message from a base station (BS), determining, within the set of subframes, at least one narrowband region for receiving the paging message, and monitoring for the paging message in the at least one narrowband region within the set of subframes.

CROSS-REFERENCE TO RELATED APPLICATION & PRIORITY CLAIM

This application is a continuation of U.S. patent application Ser. No.15/009,739, filed Jan. 28, 2016, which claims the benefit of U.S.Provisional Patent Application Ser. No. 62/110,181, filed Jan. 30, 2015,and U.S. Provisional Patent Application Ser. No. 62/113,936, filed Feb.9, 2015, all of which are herein incorporated by reference in theirentirety for all applicable purposes.

BACKGROUND Field of the Disclosure

Certain aspects of the present disclosure generally relate to wirelesscommunications and, more specifically, to enhanced paging procedures fordevices with limited communications resources, such as machine typecommunication(s) (MTC) devices and enhanced or evolved MTC (eMTC)devices. The term MTC generally applies to a broad class of devices inwireless communications including, but not limited to: Internet ofThings (IoT) devices, Internet of Everything (IoE) devices, wearabledevices and low cost devices.

Description of Related Art

Wireless communication systems are widely deployed to provide varioustypes of communication content such as voice, data, and so on. Thesesystems may be multiple-access systems capable of supportingcommunication with multiple users by sharing the available systemresources (e.g., bandwidth and transmit power). Examples of suchmultiple-access systems include code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, 3rd Generation PartnershipProject (3GPP) Long Term Evolution (LTE) including LTE-Advanced systemsand orthogonal frequency division multiple access (OFDMA) systems.

Generally, a wireless multiple-access communication system cansimultaneously support communication for multiple wireless terminals.Each terminal communicates with one or more base stations viatransmissions on the forward and reverse links. The forward link (ordownlink) refers to the communication link from the base stations to theterminals, and the reverse link (or uplink) refers to the communicationlink from the terminals to the base stations. This communication linkmay be established via a single-input single-output, multiple-inputsingle-output or a multiple-input multiple-output (MIMO) system.

A wireless communication network may include a number of base stationsthat can support communication for a number of wireless devices.Wireless devices may include user equipments (UEs). Some UEs may beconsidered machine-type communication (MTC) UEs, which may includeremote devices, that may communicate with a base station, another remotedevice, or some other entity.

Machine type communications (MTC) may refer to communication involvingat least one remote device on at least one end of the communication andmay include forms of data communication which involve one or moreentities that do not necessarily need human interaction. MTC UEs mayinclude UEs that are capable of MTC communications with MTC serversand/or other MTC devices through Public Land Mobile Networks (PLMN), forexample.

SUMMARY

The systems, methods, and devices of the disclosure each have severalaspects, no single one of which is solely responsible for its desirableattributes. Without limiting the scope of this disclosure as expressedby the claims which follow, some features will now be discussed briefly.After considering this discussion, and particularly after reading thesection entitled “Detailed Description” one will understand how thefeatures of this disclosure provide advantages that include improvedcommunications between access points and stations in a wireless network.

Techniques and apparatus are provided herein for enhancing pagingprocedures in MTC and eMTC. MTC/eMTC devices include devices such assensors, meters, monitors, location tags, drones, trackers,robots/robotic devices, etc. To enhance coverage of certain devices,such as MTC devices, “bundling” may be utilized, in which certaintransmissions are sent as a bundle of transmissions, for example, withthe same information transmitted over multiple subframes. Certainaspects of present disclose relate to determining resources used forpaging and determining a bundling size for paging.

Certain aspects of the present disclosure provide a method for wirelesscommunications by a user equipment (UE). The method generally includesdetermining a set of subframes corresponding to a paging occasion forthe UE to receive a paging message from a base station (BS),determining, within the set of subframes, at least one narrowband regionfor receiving the paging message, and monitoring for the paging messagein the at least one narrowband region within the set of subframes.

Certain aspects of the present disclosure provide an apparatus forwireless communications. The apparatus generally includes means fordetermining a set of subframes corresponding to a paging occasion forthe UE to receive a paging message from a BS, means for determining,within the set of subframes, at least one narrowband region forreceiving the paging message, and means for monitoring for the pagingmessage in the at least one narrowband region within the set ofsubframes.

Certain aspects of the present disclosure provide an apparatus forwireless communications. The apparatus generally includes at least oneprocessor configured to determine a set of subframes corresponding to apaging occasion for the UE to receive a paging message from a BS,determine, within the set of subframes, at least one narrowband regionfor receiving the paging message, and monitor for the paging message inthe at least one narrowband region within the set of subframes. Theapparatus may further include a memory coupled with the at least oneprocessor.

Certain aspects of the present disclosure provide a computer readablemedium having computer executable code stored thereon. The computerexecutable code generally includes code for determining a set ofsubframes corresponding to a paging occasion for the UE to receive apaging message from a BS, code for determining, within the set ofsubframes, at least one narrowband region for receiving the pagingmessage, and code for monitoring for the paging message in the at leastone narrowband region within the set of subframes.

Certain aspects of the present disclosure provide a method for wirelesscommunications by a BS. The method generally includes determining a setof subframes corresponding to a paging occasion for transmitting apaging message to a UE, determining, within the set of subframes, atleast one narrowband region for transmitting the paging message to theUE, and transmitting the paging message to the UE in the at least onenarrowband region of the set of subframes.

Certain aspects of the present disclosure provide an apparatus forwireless communications. The apparatus generally includes means fordetermining a set of subframes corresponding to a paging occasion fortransmitting a paging message to a UE, means for determining, within theset of subframes, at least one narrowband region for transmitting thepaging message to the UE, and means for transmitting the paging messageto the UE in the at least one narrowband region of the set of subframes.

Certain aspects of the present disclosure provide an apparatus forwireless communications. The apparatus generally includes at least oneprocessor configured to determine a set of subframes corresponding to apaging occasion for transmitting a paging message to a UE, anddetermine, within the set of subframes, at least one narrowband regionfor transmitting the paging message to the UE. The apparatus may alsoinclude a transmitter configured to transmit the paging message to theUE in the at least one narrowband region of the set of subframes. Theapparatus may further include a memory coupled with the at least oneprocessor.

Certain aspects of the present disclosure provide a computer readablemedium having computer executable code stored thereon. The computerexecutable code generally includes code for determining a set ofsubframes corresponding to a paging occasion for transmitting a pagingmessage to a UE, code for determining, within the set of subframes, atleast one narrowband region for transmitting the paging message to theUE, and code for transmitting the paging message to the UE in the atleast one narrowband region of the set of subframes.

Numerous other aspects are provided including methods, apparatus,systems, computer program products, and processing systems. To theaccomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the appended drawings. It is to be noted,however, that the appended drawings illustrate only certain typicalaspects of this disclosure and are therefore not to be consideredlimiting of its scope, for the description may admit to other equallyeffective aspects.

FIG. 1 is a block diagram conceptually illustrating an example wirelesscommunication network, in accordance with certain aspects of the presentdisclosure.

FIG. 2 is a block diagram conceptually illustrating an example of anevolved nodeB (eNB) in communication with a user equipment (UE) in awireless communications network, in accordance with certain aspects ofthe present disclosure.

FIG. 3 is a block diagram conceptually illustrating an example framestructure for a particular radio access technology (RAT) for use in awireless communications network, in accordance with certain aspects ofthe present disclosure.

FIG. 4 illustrates example subframe formats for the downlink with anormal cyclic prefix, in accordance with certain aspects of the presentdisclosure.

FIGS. 5 and 5A illustrate an example of machine type communications(MTC) co-existence within a wideband system, such as long term evolution(LTE), in accordance with certain aspects of the present disclosure.

FIG. 6 illustrates example operations for wireless communications, by aUE, in accordance with certain aspects of the present disclosure.

FIG. 6A illustrates example means capable of performing the operationsset forth in FIG. 6.

FIG. 7 illustrates example operations for wireless communications, by aBS, in accordance with certain aspects of the present disclosure.

FIG. 7A illustrates example means capable of performing the operationsset forth in FIG. 7.

FIG. 8 illustrates an example of transmissions from multiple devicesthat may be multiplexed together, in accordance with certain aspects ofthe present disclosure.

FIGS. 9-10 illustrate example call flows for determining the bundlingsize of a paging message transmitted to a UE by a BS, in accordance withcertain aspects of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation.

DETAILED DESCRIPTION

Aspects of the present disclosure provide techniques and apparatus forenhanced paging procedures for devices with limited communicationresources, such as MTC devices (e.g., low cost MTC devices, low costeMTC devices). MTC devices may be implemented as narrowband IoT (NB-IoT)devices. The low cost MTC devices may co-exist with other legacy devicesin a particular radio access technology (RAT) (e.g., long term evolution(LTE)) and may operate on one or more narrowband regions partitioned outof an available system bandwidth that is supported by the particularRAT. The low cost MTC devices may also support different modes ofoperation, such as a coverage enhanced mode (e.g., where repetitions ofthe same message may be bundled or transmitted across multiplesubframes), a normal coverage mode (e.g., where repetitions may not betransmitted), etc.

Accordingly, as will be described in more detail below, the techniquespresented herein may allow for low cost devices to determine, from theavailable system bandwidth, which narrowband region(s) the low costdevices should monitor for a bundled paging message transmitted from abase station (BS)/network. As will also be described in more detailbelow, techniques presented herein may also allow for the determinationand/or adaptation of the bundling size for the paging message based onone or more triggers.

The techniques described herein may be used for various wirelesscommunication networks such as Code Division Multiple Access (CDMA)networks, Time Division Multiple Access (TDMA) networks, FrequencyDivision Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA)networks, Single-Carrier FDMA (SC-FDMA) networks, etc. The terms“network” and “system” are often used interchangeably. A CDMA networkmay implement a radio technology such as Universal Terrestrial RadioAccess (UTRA), cdma2000, etc. UTRA includes Wideband-CDMA (W-CDMA), TimeDivision Synchronous CDMA (TD-SCDMA), and other variants of CDMA.cdma2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network mayimplement a radio technology such as Global System for MobileCommunications (GSM). An OFDMA network may implement a radio technologysuch as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM®, etc. UTRA andE-UTRA are part of Universal Mobile Telecommunication System (UMTS).3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A), in bothfrequency division duplex (FDD) and time division duplex (TDD), are newreleases of UMTS that use E-UTRA, which employs OFDMA on the downlinkand SC-FDMA on the uplink. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM aredescribed in documents from an organization named “3rd GenerationPartnership Project” (3GPP). cdma2000 and UMB are described in documentsfrom an organization named “3rd Generation Partnership Project 2”(3GPP2). The techniques described herein may be used for the wirelessnetworks and radio technologies mentioned above as well as otherwireless networks and radio technologies. For clarity, certain aspectsof the techniques are described below for LTE/LTE-A, and LTE/LTE-Aterminology is used in much of the description below. LTE and LTE-A arereferred to generally as LTE.

FIG. 1 illustrates an example wireless communication network 100 withbase stations (BSs) and user equipments (UEs), in which aspects of thepresent disclosure may be practiced.

For example, one or more paging procedure enhancements for certain UEs120 (e.g., low cost machine type communication (MTC) UEs, low costenhanced MTC (eMTC) UEs, etc.) in the wireless communication network 100may be supported. According to the techniques presented herein, the eNBs110 and UE(s) 120 in the wireless communication network 100 may be ableto determine, from the available system bandwidth supported by thewireless communication network 100, which narrowband region(s) the UE(s)120 should monitor for a bundled paging message transmitted from theeNBs 110 in the wireless communication network 100. Also, according totechniques described herein, the eNBs 110 and/or UE(s) 120 in thewireless communication network 100 may be able to determine and/or adaptthe bundling size for the paging message based on one or more triggersin the wireless communication network 100.

The wireless communication network 100 may be a long term evolution(LTE) network or some other wireless network. Wireless communicationnetwork 100 may include a number of evolved Node Bs (eNBs) 110 and othernetwork entities. An eNB is an entity that communicates with UEs and mayalso be referred to as a base station (BS), a Node B, an access point(AP), etc. Each eNB may provide communication coverage for a particulargeographic area. In 3GPP, the term “cell” can refer to a coverage areaof an eNB and/or an eNB subsystem serving this coverage area, dependingon the context in which the term is used.

An eNB may provide communication coverage for a macro cell, a pico cell,a femto cell, and/or other types of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). An eNB for a macro cell may bereferred to as a macro eNB. An eNB for a pico cell may be referred to asa pico eNB. An eNB for a femto cell may be referred to as a femto eNB ora home eNB (HeNB). In the example shown in FIG. 1, an eNB 110 a may be amacro eNB for a macro cell 102 a, an eNB 110 b may be a pico eNB for apico cell 102 b, and an eNB 110 c may be a femto eNB for a femto cell102 c. An eNB may support one or multiple (e.g., three) cells. The terms“eNB”, “base station,” and “cell” may be used interchangeably herein.

Wireless communication network 100 may also include relay stations. Arelay station is an entity that can receive a transmission of data froman upstream station (e.g., an eNB or a UE) and send a transmission ofthe data to a downstream station (e.g., a UE or an eNB). A relay stationmay also be a UE that can relay transmissions for other UEs. In theexample shown in FIG. 1, a relay (station) eNB 110 d may communicatewith macro eNB 110 a and a UE 120 d in order to facilitate communicationbetween eNB 110 a and UE 120 d. A relay station may also be referred toas a relay eNB, a relay base station, a relay, etc.

Wireless communication network 100 may be a heterogeneous network thatincludes eNBs of different types, e.g., macro eNBs, pico eNBs, femtoeNBs, relay eNBs, etc. These different types of eNBs may have differenttransmit power levels, different coverage areas, and different impact oninterference in wireless communication network 100. For example, macroeNBs may have a high transmit power level (e.g., 5 to 40 W) whereas picoeNBs, femto eNBs, and relay eNBs may have lower transmit power levels(e.g., 0.1 to 2 W).

A network controller 130 may couple to a set of eNBs and may providecoordination and control for these eNBs. Network controller 130 maycommunicate with the eNBs via a backhaul. The eNBs may also communicatewith one another, e.g., directly or indirectly via a wireless orwireline backhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelesscommunication network 100, and each UE may be stationary or mobile. A UEmay also be referred to as an access terminal, a terminal, a mobilestation (MS), a subscriber unit, a station (STA), etc. A UE may be acellular phone, a personal digital assistant (PDA), a wireless modem, awireless communication device, a handheld device, a laptop computer, acordless phone, a wireless local loop (WLL) station, a tablet, a smartphone, a netbook, a smartbook, an ultrabook, an entertainment device(e.g., music player, gaming device, etc.), a camera, a vehicular device,a navigation device, a drone, a robot/robotic device, a wearable device(e.g., smart watch, smart clothing, smart wristband, smart ring, smartbracelet, smart glasses, virtual reality goggles), etc.

One or more UEs 120 in the wireless communication network 100 (e.g., anLTE network) may also be low cost, low data rate devices, e.g., such aslow cost MTC UEs, low cost eMTC UEs, etc. The low cost UEs may co-existwith legacy and/or advanced UEs in the LTE network and may have one ormore capabilities that are limited when compared to the other UEs (e.g.,non-low cost UEs) in the wireless network. For example, when compared tolegacy and/or advanced UEs in the LTE network, the low cost UEs mayoperate with one or more of the following: a reduction in maximumbandwidth (relative to legacy UEs), a single receive radio frequency(RF) chain, reduction of peak rate, reduction of transmit power, rank 1transmission, half duplex operation, etc. As used herein, devices withlimited communication resources, such as MTC devices, eMTC devices, etc.are referred to generally as low cost UEs. Similarly, legacy devices,such as legacy and/or advanced UEs (e.g., in LTE) are referred togenerally as non-low cost UEs.

FIG. 2 is a block diagram of a design of BS/eNB 110 and UE 120, whichmay be one of the BSs/eNBs 110 and one of the UEs 120, respectively, inFIG. 1. BS 110 may be equipped with T antennas 234 a through 234 t, andUE 120 may be equipped with R antennas 252 a through 252 r, where ingeneral T 1 and

At BS 110, a transmit processor 220 may receive data from a data source212 for one or more UEs, select one or more modulation and codingschemes (MCSs) for each UE based on channel quality indicators (CQIs)received from the UE, process (e.g., encode and modulate) the data foreach UE based on the MCS(s) selected for the UE, and provide datasymbols for all UEs. Transmit processor 220 may also process systeminformation (e.g., for semi-static resource partitioning information(SRPI), etc.) and control information (e.g., CQI requests, grants, upperlayer signaling, etc.) and provide overhead symbols and control symbols.Processor 220 may also generate reference symbols for reference signals(e.g., the common reference signal (CRS)) and synchronization signals(e.g., the primary synchronization signal (PSS) and secondarysynchronization signal (SSS)). A transmit (TX) multiple-inputmultiple-output (MIMO) processor 230 may perform spatial processing(e.g., precoding) on the data symbols, the control symbols, the overheadsymbols, and/or the reference symbols, if applicable, and may provide Toutput symbol streams to T modulators (MODs) 232 a through 232 t. EachMOD 232 may process a respective output symbol stream (e.g., for OFDM,etc.) to obtain an output sample stream. Each MOD 232 may furtherprocess (e.g., convert to analog, amplify, filter, and upconvert) theoutput sample stream to obtain a downlink signal. T downlink signalsfrom modulators 232 a through 232 t may be transmitted via T antennas234 a through 234 t, respectively.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom BS 110 and/or other BSs and may provide received signals todemodulators (DEMODs) 254 a through 254 r, respectively. Each DEMOD 254may condition (e.g., filter, amplify, downconvert, and digitize) itsreceived signal to obtain input samples. Each DEMOD 254 may furtherprocess the input samples (e.g., for OFDM, etc.) to obtain receivedsymbols. A MIMO detector 256 may obtain received symbols from all Rdemodulators 254 a through 254 r, perform MIMO detection on the receivedsymbols if applicable, and provide detected symbols. A receive processor258 may process (e.g., demodulate and decode) the detected symbols,provide decoded data for UE 120 to a data sink 260, and provide decodedcontrol information and system information to a controller/processor280. A channel processor may determine reference signal received power(RSRP), received signal strength indicator (RSSI), reference signalreceived quality (RSRQ), CQI, etc.

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports comprising RSRP, RSSI, RSRQ, CQI, etc.) fromcontroller/processor 280. Processor 264 may also generate referencesymbols for one or more reference signals. The symbols from transmitprocessor 264 may be precoded by a TX MIMO processor 266 if applicable,further processed by MODs 254 a through 254 r (e.g., for SC-FDM, OFDM,etc.), and transmitted to BS 110. At BS 110, the uplink signals from UE120 and other UEs may be received by antennas 234, processed by DEMODs232, detected by a MIMO detector 236 if applicable, and furtherprocessed by a receive processor 238 to obtain decoded data and controlinformation sent by UE 120. Processor 238 may provide the decoded datato a data sink 239 and the decoded control information tocontroller/processor 240. BS 110 may include communication unit 244 andcommunicate to network controller 130 via communication unit 244.Network controller 130 may include communication unit 294,controller/processor 290, and memory 292.

Controllers/processors 240 and 280 may direct the operation at BS 110and UE 120, respectively. For example, controller/processor 240 and/orother processors and modules at BS 110 may perform or direct operations700 illustrated in FIG. 7 and/or other processes for the techniquesdescribed herein. Similarly, controller/processor 280 and/or otherprocessors and modules at UE 120 may perform or direct operations 600illustrated in FIG. 6 and/or processes for the techniques describedherein. Memories 242 and 282 may store data and program codes for BS 110and UE 120, respectively. A scheduler 246 may schedule UEs for datatransmission on the downlink and/or uplink.

FIG. 3 shows an exemplary frame structure 300 for FDD in LTE. Thetransmission timeline for each of the downlink and uplink may bepartitioned into units of radio frames. Each radio frame may have apredetermined duration (e.g., 10 milliseconds (ms)) and may bepartitioned into 10 subframes with indices of 0 through 9. Each subframemay include two slots. Each radio frame may thus include 20 slots withindices of 0 through 19. Each slot may include L symbol periods, e.g.,seven symbol periods for a normal cyclic prefix (as shown in FIG. 2) orsix symbol periods for an extended cyclic prefix. The 2L symbol periodsin each subframe may be assigned indices of 0 through 2L−1.

In LTE, an eNB may transmit a primary synchronization signal (PSS) and asecondary synchronization signal (SSS) on the downlink in the center1.08 MHz of the system bandwidth for each cell supported by the eNB. ThePSS and SSS may be transmitted in symbol periods 6 and 5, respectively,in subframes 0 and 5 of each radio frame with the normal cyclic prefix,as shown in FIG. 3. The PSS and SSS may be used by UEs for cell searchand acquisition. The eNB may transmit a cell-specific reference signal(CRS) across the system bandwidth for each cell supported by the eNB.The CRS may be transmitted in certain symbol periods of each subframeand may be used by the UEs to perform channel estimation, channelquality measurement, and/or other functions. The eNB may also transmit aphysical broadcast channel (PBCH) in symbol periods 0 to 3 in slot 1 ofcertain radio frames. The PBCH may carry some system information. TheeNB may transmit other system information such as system informationblocks (SIBs) on a physical downlink shared channel (PDSCH) in certainsubframes. The eNB may transmit control information/data on a physicaldownlink control channel (PDCCH) in the first B symbol periods of asubframe, where B may be configurable for each subframe. The eNB maytransmit traffic data and/or other data on the PDSCH in the remainingsymbol periods of each subframe.

The PSS, SSS, CRS, and PBCH in LTE are described in 3GPP TS 36.211,entitled “Evolved Universal Terrestrial Radio Access (E-UTRA); PhysicalChannels and Modulation,” which is publicly available.

FIG. 4 shows two example subframe formats 410 and 420 for the downlinkwith a normal cyclic prefix. The available time frequency resources forthe downlink may be partitioned into resource blocks. Each resourceblock may cover 12 subcarriers in one slot and may include a number ofresource elements. Each resource element may cover one subcarrier in onesymbol period and may be used to send one modulation symbol, which maybe a real or complex value.

Subframe format 410 may be used for an eNB equipped with two antennas. ACRS may be transmitted from antennas 0 and 1 in symbol periods 0, 4, 7,and 11. A reference signal is a signal that is known a priori by atransmitter and a receiver and may also be referred to as pilot. A CRSis a reference signal that is specific for a cell, e.g., generated basedon a cell identity (ID). In FIG. 4, for a given resource element withlabel Ra, a modulation symbol may be transmitted on that resourceelement from antenna a, and no modulation symbols may be transmitted onthat resource element from other antennas. Subframe format 420 may beused for an eNB equipped with four antennas. A CRS may be transmittedfrom antennas 0 and 1 in symbol periods 0, 4, 7, and 11 and fromantennas 2 and 3 in symbol periods 1 and 8. For both subframe formats410 and 420, a CRS may be transmitted on evenly spaced subcarriers,which may be determined based on cell ID. Different eNBs may transmittheir CRSs on the same or different subcarriers, depending on their cellIDs. For both subframe formats 410 and 420, resource elements not usedfor the CRS may be used to transmit data (e.g., traffic data, controldata, and/or other data).

An interlace structure may be used for each of the downlink and uplinkfor FDD in LTE. For example, Q interlaces with indices of 0 through Q−1may be defined, where Q may be equal to 4, 6, 8, 10, or some othervalue. Each interlace may include subframes that are spaced apart by Qframes. In particular, interlace q may include subframes q, q+Q, q+2Q,etc., where q∈{0, . . . , Q−1}.

The wireless network may support hybrid automatic retransmission request(HARQ) for data transmission on the downlink and uplink. For HARQ, atransmitter (e.g., an eNB 110) may send one or more transmissions of apacket until the packet is decoded correctly by a receiver (e.g., a UE120) or some other termination condition is encountered. For synchronousHARQ, all transmissions of the packet may be sent in subframes of asingle interlace. For asynchronous HARQ, each transmission of the packetmay be sent in any subframe.

A UE may be located within the coverage of multiple eNBs. One of theseeNBs may be selected to serve the UE. The serving eNB may be selectedbased on various criteria such as received signal strength, receivedsignal quality, path loss, etc. Received signal quality may bequantified by a signal-to-interference-plus-noise ratio (SINR), or areference signal received quality (RSRQ), or some other metric. The UEmay operate in a dominant interference scenario in which the UE mayobserve high interference from one or more interfering eNBs.

As mentioned above, one or more UEs in the wireless communicationnetwork (e.g., wireless communication network 100) may be devices thathave limited communication resources, such as low cost UEs, as comparedto other (non-low cost) devices in the wireless communication network.

Example Low Cost MTC

In some systems, for example, in LTE Rel-13, a low cost UE may belimited to a particular narrowband assignment (e.g., of no more than sixresource blocks (RBs)) within the available system bandwidth. However,the low cost UE may be able to re-tune (e.g., to operate and/or camp) todifferent narrowband regions within the available system bandwidth ofthe LTE system, for example, in order to co-exist within the LTE system.

As another example of coexistence within the LTE system, low cost UEsmay be able to receive (with repetition) legacy physical broadcastchannel (PBCH) (e.g., the LTE physical channel that, in general, carriesparameters that may be used for initial access to the cell) and supportone or more legacy physical random access channel (PRACH) formats. Forexample, the low cost UE may be able to receive the legacy PBCH with oneor more additional repetitions of the PBCH across multiple subframes(e.g., bundled). As another example, the low cost UE may be able totransmit one or more repetitions of PRACH (e.g., with one or more PRACHformats supported) to an eNB (e.g., eNB 110) in the LTE system. ThePRACH can be used to identify the low cost UE. Also, the number ofrepeated PRACH attempts can be configured by the eNB.

The low cost UE may also be a link budget limited device and may operatein different modes of operation (e.g., using different numbers ofrepetitions for messages transmitted to or from the low cost UE) basedon its link budget limitation. For example, in some cases, the low costUE may operate in a normal coverage mode in which there is little to norepetition (e.g., the amount of repetition needed for the UE tosuccessfully receive and/or transmit a message may be low or repetitionmay not even be needed). Alternatively, in some cases, the low cost UEmay operate in a coverage enhancement (CE) mode in which there may behigh amounts of repetition. For example, for a 328 bit payload, a lowcost UE in CE mode may need 150 or more repetitions of the payload inorder to successfully transmit and/or receive the payload.

In some cases (e.g., for LTE Rel-13), the low cost UE may have limitedcapabilities with respect to its reception of broadcast and unicasttransmissions. For example, the maximum transport block (TB) size for abroadcast transmission received by the low cost UE may be limited to1000 bits. Additionally, in some cases, the low cost UE may not be ableto receive more than one unicast TB in a subframe. In some cases (e.g.,for both the CE mode and normal mode described above), the low cost UEmay not be able to receive more than one broadcast TB in a subframe.Further, in some cases, the low cost UE may not be able to receive botha unicast TB and a broadcast TB in a subframe.

For MTC, low cost UEs that co-exist in the LTE system may also supportnew messages for certain procedures, such as paging, random accessprocedure, etc. (e.g., as opposed to conventional messages used in LTEfor these procedures). In other words, these new messages for paging,random access procedure, etc. may be separate from the messages used forsimilar procedures associated with non-low cost UEs. For example, ascompared to conventional paging messages used in LTE, low cost UEs maybe able to monitor and/or receive paging messages that non-low cost UEsmay not be able to monitor and/or receive. Similarly, as compared toconventional random access response (RAR) messages used in aconventional random access procedure, low cost UEs may be able toreceive RAR messages that non-low cost UEs may not be able to receive.The new paging and RAR messages associated with low cost UEs may also berepeated one or more times (e.g., bundled). In addition, differentnumbers of repetitions (e.g., different bundling sizes) for the newmessages may be supported.

Example MTC Coexistence within a Wideband System

As mentioned above, MTC and/or eMTC operation may be supported (e.g., incoexistence with LTE or some other RAT) in the wireless communicationnetwork (e.g., wireless communication network 100). FIGS. 5 and 5Aillustrate an example of how low cost UEs in MTC operation may co-existwithin a wideband system, such as LTE.

As illustrated in the example frame structure 500 of FIG. 5, subframesassociated with MTC and/or eMTC operation may be time divisionmultiplexed (TDM) with regular subframes associated with LTE (or someother RAT). For example, regular subframe may occurring at timeinstances 502, 506, and 510 can be TDM with MTC subframes occurring attime instances 504, 508, and 512. As shown in FIG. 5, in one exampleimplementation, the number of subframe associated (e)MTC operation maybe relatively small compared to the number of regular subframes.

Additionally or alternatively, as illustrated in the example framestructure 500A of FIG. 5A, one or more narrowbands used by low cost UEsin MTC may be frequency division multiplexed (FDM) within the widerbandwidth supported by LTE. Multiple narrowband regions may be supportedfor MTC and/or eMTC operation, with each narrowband region spanning abandwidth that is no greater than a total of 6 RBs. In some cases, eachlow cost UE in MTC operation may operate within one narrowband region(e.g., at 1.4 MHz or 6 RBs) at a time. However, low cost UEs in MTCoperation, at any given time, may re-tune to other narrowband regions inthe wider system bandwidth. In some examples, multiple low cost UEs maybe served by the same narrowband region. In other examples, multiple lowcost UEs may be served by different narrowband regions (e.g., with eachnarrowband region spanning 6 RBs). In yet other examples, differentcombinations of low cost UEs may be served by one or more samenarrowband regions and/or one or more different narrowband regions.

As shown in FIG. 5A, in a subframe 500A, the low cost UE can monitor awideband region 508A for legacy control information and wideband regions502A and 506A for data. The low cost UEs may operate (e.g.,monitor/receive/transmit) within the narrowband regions for variousdifferent operations. For example, as shown in FIG. 5A, a firstnarrowband region 504A (e.g., spanning no more than 6 RBs) of a subframemay be monitored by one or more low cost UEs for either a primarysynchronization signal (PSS), a secondary synchronization signal (SSS),a physical broadcast channel (PBCH), MTC signaling, or pagingtransmission from a BS in the wireless communication network. As alsoshown in FIG. 5A, the low cost UE can retune to a second narrowbandregion 510A (e.g., also spanning no more than 6 RBs of the widebanddata) of a subframe to transmit a RACH or data previously configured insignaling received from a BS. In some cases, the second narrowbandregion 510A may be utilized by the same low cost UEs that utilized thefirst narrowband region 504A (e.g., the low cost UEs may have re-tunedto the second narrowband region to transmit after monitoring in thefirst narrowband region). In some cases (although not shown), the secondnarrowband region 510A may be utilized by different low cost UEs thanthe low cost UEs that utilized the first narrowband region 504A.

Although the examples described herein assume a narrowband of 6 RBS,those skilled in the art will recognize that the techniques presentedherein may also be applied to different sizes of narrowband regions.

Example Paging Enhancements for Low Cost EMTC

As mentioned above, in certain systems (e.g., LTE Rel-13 systems),narrowband operation for enhanced machine type communications (eMTC) maybe supported. Further, as also mentioned above, different modes ofoperation for low cost devices, such as low cost user equipment (UEs) ineMTC, which may use different amounts of repetition before a message issuccessfully received and/or transmitted by the low cost UEs, may alsobe supported. In some situations, due to support for narrowbandoperation, the base station (BS) and/or the low cost UEs may not knowwhich narrowband region out of the available system bandwidth a pagingmessage should be transmitted (e.g., by the BS) or monitored (e.g., bythe low cost UEs). Further, in some situations, due to the differentcoverage modes supported, the BS may know how much bundling of thepaging messages may be needed for the low cost UEs to successfullyreceive the paging message.

Accordingly, aspects of the present disclosure provide techniques fordetermining, from the available system bandwidth, which narrowbandregion(s) the low cost UEs should monitor for a bundled paging messagetransmitted from a BS. Further, techniques presented herein may alsoallow for determining and/or adapting the bundling size of the pagingmessage based on one or more triggers.

FIG. 6 illustrates example operations 600 for wireless communications,in accordance with certain aspects of the present disclosure. Theoperations 600 can be performed by a UE, such as a low cost UE, whichmay be one of the UEs 120 illustrated in FIGS. 1 and 2. The operations600 may begin, at 602, by determining a set of subframes correspondingto a bundled paging occasion for the UE to receive a bundled pagingmessage from a BS. At 604, the UE determines, within the set ofsubframes, at least one narrowband region for receiving the pagingmessage. At 606, the UE monitors for the paging message in the at leastone narrowband region within the set of subframes. FIG. 6A illustratesexample means capable of performing the operations set forth in FIG. 6.

FIG. 7 illustrates example operations 700 for wireless communications,in accordance with certain aspects of the present disclosure. Theoperations 700 can be performed by a BS, such as one of the BSs/eNBs 110illustrated in FIGS. 1 and 2, and may be corresponding network sideoperations to the operations 600. The operations 700 may begin, at 702,by determining a set of subframes corresponding to a bundled pagingoccasion for transmitting a bundled paging message to a UE, such as alow cost UE. At 704, the BS determines, within the set of subframes, atleast one narrowband region for transmitting the paging message to theUE. At 706, the BS transmits the paging message to the UE in the atleast one narrowband region of the set of subframes. FIG. 7A illustratesexample means capable of performing the operations set forth in FIG. 7.

As mentioned above, in some systems (e.g., for LTE Rel-13), the pagingprocedure for low cost UEs may allow for narrowband operation and/orpaging repetition (e.g., bundling) with varying bundle sizes (e.g.,multiple subframe bundling sizes may be supported). As used herein, thebundling size of a paging message may refer to the number of subframesin which the paging message is transmitted/repeated to the low cost UE.

According to certain aspects, in order for devices (e.g., low cost UEsand/or BSs) in the wireless communication network to know which pagingresource the low cost UEs should monitor for a paging messagetransmitted from the BS, the paging resource may first need to bedetermined. For example, in certain systems (e.g., LTE Rel-13 systems),the paging resource may include the paging frame (PF), paging occasion(PO) and paging narrowband region (PNB) (e.g., as opposed to just the PFand PO in conventional paging procedures).

The PF, in general, may refer to one radio frame, which may contain oneor multiple POs in which a bundled paging message may be transmitted.The PO, in general, may refer to a subframe within a PF in which the BS/network may page the low cost UE. For example, in a PO configured forthe low cost UE, the low cost UE may monitor the physical downlinkcontrol channel (PDCCH) or enhanced PDCCH (ePDCCH) for any transmissionsof a paging radio network temporary identifier (P-RNTI) addressing thepaging message. According to certain aspects, a bundled PO may refer toa plurality of subframes in which the BS/network may transmit a bundledpaging message to the low cost UE.

Example Paging Resources Determination

According to certain aspects, the determination of the PF and bundled PO(which may correspond to a plurality of subframes in which a bundledpaging message may be transmitted from the BS) may be determined basedon formulas currently used for determining PF and PO in conventionalpaging procedures (e.g., for legacy LTE). These formulas (for PF and PO)may be based, in part, on a system frame number (SFN) and a UE_ID thatuniquely identifies the low cost UE. After the determination of the PFand bundled PO, the low cost UE and/or BS may determine at least onenarrowband (NB) region in which the low cost UE may monitor for abundled paging message transmitted from the BS (e.g., tuning to anappropriate narrowband region to monitor for the paging message). FIG.8, for example, is time/frequency graph illustrating an example of howdifferent narrowband regions for low cost UEs may be utilized in a MTCpaging cycle.

As shown in FIG. 8, a legacy paging cycle utilized for legacy UEs and aMTC paging cycle utilized for low cost UEs may co-exist within the samewireless communication system. For example, legacy pages (e.g., that donot use bundling) associated with the legacy paging cycle, however, maybe wideband pages restricted to a certain bandwidth, as compared to theMTC page associated with the MTC paging cycle that may be transmitted,with bundling, on one or more narrowband regions partitioned out of thetotal available bandwidth. For example, as shown in FIG. 8, during theMTC paging cycle one or more low cost UEs may monitor for a MTC pagethat may be transmitted in narrowband regions 1 (806 and 812), while oneor more different low cost UEs may monitor for a MTC page that may betransmitted in narrowband regions 2 (804 and 810). During the legacypaging cycle, legacy UEs may monitor for a legacy page transmitted inwideband regions 802 and 808. As shown in FIG. 8, the legacy pagingcycle and the MTC paging cycle may overlap.

According to certain aspects, the MTC pages (shown in FIG. 8) may bebundled paging messages. As mentioned above, the bundled paging messagemay refer to the number of subframes in which the paging message istransmitted/repeated in one MTC paging cycle. Although not shown, theamount of bundling for MTC page in narrowband regions 1 804 and 810 andfor MTC page in narrowband regions 2 806 and 812 may be the same (asshown) or different (not shown). Further, although not shown, the amountof bundling for the MTC pages may vary between paging cycles.

According to certain aspects, the determination of the narrowband regionmay be based on a default narrowband region. For example, in some cases,the default narrowband region may include the center 6 RBs of theavailable system bandwidth and the low cost UE may be configured toalways tune to the center 6 RBs. In general, however, those of ordinaryskill in the art will appreciate that other default narrowband regionsmay be supported/configured.

According to certain aspects, the determination of the narrowband regionmay be based on an identification (ID) of the low cost UE. For example,in some cases, the UE_ID may be similar to the UE_ID utilized in thedetermination of PF and PO in conventional paging procedures. In somecases, the UE_ID may be an ID that uniquely identifies the low cost UEbut that is different from the UE_ID utilized in conventional pagingprocedures. In some aspects, if there are one or more narrowband regionsdetermined, the UE_ID may be utilized to randomize the low cost UEsacross the one or more determined narrowband regions.

According to certain aspects, the determination of the narrowband regionmay be based on signaling from the B S. For example, in one case, thelow cost UE may receive radio resource control (RRC) signaling and/orNon-Access Stratum (NAS) signaling explicitly indicating whichnarrowband region the low cost UE should monitor for a bundled pagingmessage transmitted from the BS. In some cases, the low cost UE mayimplicitly determine, based on signaling indicating the size of thebundled paging message, which narrowband region it should monitor for abundled paging message transmitted from the BS. For example, one or morelow cost UEs in the wireless communication system may be groupedtogether based on bundling sizes (e.g., depending on radio conditionsfor that particular group, etc.) and the different groups of low costUEs may be assigned to different narrowband regions within the availablesystem bandwidth.

According to certain aspects, instead of reusing conventional proceduresfor the determination of PF and PO, the determination of the pluralityof subframes corresponding to the (bundled) PO and the one or morenarrowband regions may be jointly determined (e.g., determined based ona same algorithm/formula). In certain aspects, the one or morenarrowband regions within each subframe of the plurality of subframesmay be considered as additional PO resources in time and/or frequency.For example, if there are N narrowband regions, then the devices (e.g.,BS and/or low cost UEs) may determine that there are N times the POresources. In certain aspects, the joint determination of the one ormore narrowband regions (e.g., the N*PO PO resources) and plurality ofsubframes may be based on the UE_ID and/or signaling from the BS.

The various techniques described above may be combined in order todetermine which narrowband region, out of the available systembandwidth, the low cost UE should monitor for a bundled paging messagetransmitted from the BS. For example, in one case, the low cost UE mayinitially receive signaling explicitly indicating the narrowband region,however, if the low cost UE determines that signaling is not available,the low cost UE may resort to making the determination based on a UE_ID,default value, etc.

Example Paging Bundling Size Determination

As mentioned above, techniques described herein may also allow for theUE and/or BS to determine and/or adapt the bundling size for bundledpaging messages transmitted by the BS. For example, in some cases, thelow cost UE can determine bundling size based on signaling from the BS.In some cases, the bundling size may be determined based on thenarrowband region used by the BS to transmit the paging message to thelow cost UE. For example, as mentioned above, each of the one or morenarrowband regions partitioned out of the available system bandwidth maysupport a particular amount of bundling for the transmission of pagingmessages. Further, as also mentioned above, the amount of bundlingsupported by some of the narrowband regions may be the same (ordifferent) as the amount of bundling supported by other narrowbandregions. Thus, in some cases, upon determining which narrowband regionwill be used to transmit a paging message, the BS and/or low cost UE maydetermine, based on the supported bundling size used in that narrowbandregion, the particular bundling size that will be used for the pagingmessage. In some cases, the low cost UE may then monitor for the pagingmessage in the narrowband region of the plurality of subframes, based onthe determined bundling size. Similarly, in some cases, the BS maytransmit the paging message to the UE in the narrowband region of theplurality of subframes based on the determined bundling size.

According to certain aspects, the low cost UE may indicate a connectionmode to the network (e.g., Mode 1, Mode 2, Mode 3, etc.). The bundlingsize for the PF may be determined based on the connection mode. Forexample, a connection mode (e.g., Mode 1) may indicate that the UE isdeployed in non-mobility mode (e.g., the low cost UE is generallyexpected to be deployed in a fixed location where the UE iscamping/served under the same BS). Another connection mode (e.g., Mode2) may indicate that the UE is deployed in a regular mobility mode. Theconnection mode (e.g., Mode 1) may also indicate that the low cost UE isdeployed in a normal power preference mode and another connection mode(e.g., Mode 2) may indicate that the low cost UE is deployed in a lowpower preference mode. According to certain aspects, the connection modeof the low cost UE may determine UE behavior upon cellselection/re-selection. For example, if the low cost UE is deployed inone connection mode (e.g., Mode 1), a random access procedure may betriggered/performed. Alternatively, if the low cost UE is deployed inanother connection mode (e.g., Mode 2), for example, the low cost UE maydetermine bundling size based on a pre-configured value. In aspects, thelow cost UE may select a new value for bundling size for pagingmessages.

According to certain aspects, the BS may transmit paging messages to theUE by sending multiple bundled transmissions of the paging message tothe UE until a response from the UE is detected or until an indicationis received from the network. According to certain aspects, the multiplebundled transmissions may be of increasing bundling sizes. As oneexample, a bundling size of each bundled transmission of the multiplebundled transmissions is larger than a bundling size of the previousbundled transmission of the multiple bundled transmissions.

FIGS. 9 and 10 illustrate example call flows 900 and 1000, respectively,for determining the bundling size of the paging message transmitted tothe low cost UEs by the BS. The eNB and MTC device (e.g., a low cost UE)illustrated in FIGS. 9 and 10 may be any of the BSs/eNBs 110 and UEs120, respectively, illustrated in FIGS. 1 and 2.

According to certain aspects, as shown in FIG. 9, the bundling size maybe determined based on a bundling size of a bundled random accesschannel (RACH) transmission that is successfully decoded by the BS.

When performing a RACH (e.g., transmits RACH messages) on the uplink,the low cost UE may attempt multiple bundle sizes of the RACHtransmission until the BS is able to successfully decode the RACHtransmission. For example, as shown in FIG. 9, on a first attempt at902, the low cost UE 120 may attempt a bundling size of two for thefirst bundled RACH transmission (e.g., two repetitions of the RACHtransmission). If the first attempt fails at 904, on a second attempt at906, the low cost UE 120 can use a bundling size of three for the secondbundled RACH transmission. Similarly, if the second attempt fails at908, on a third attempt at 910, the UE can use a bundling size of fourfor a third bundled RACH transmission, etc. According to certainaspects, the determination of the bundling size for the bundled pagingmessage may be determined (e.g., by the BS) based on the size of thebundled RACH that is successfully decoded by the BS. For example, asshown, if on the third decoding attempt, the BS successfully decodes thethird bundled RACH, the BS may determine the paging bundling size basedon the third bundled RACH.

As shown in FIG. 9, if the RACH attempt succeeds, for example at 912after the third bundled RACH transmission, the eNB 110 can determine abundling size for paging based on the bundling size for the thirdbundled RACH transmission at 914.

According to certain aspects, as shown in FIG. 10, the bundling size maybe determined based on a number of attempts needed to successfullydecode (e.g., early decode) a bundled transmission from the BS.

For example, as shown in FIG. 10, the low cost UE 120 may receive abundled broadcast transmission at 1002 (e.g., with one or morerepetitions of the broadcast transmission) and may attempt to earlydecode the bundled broadcast transmission (e.g., successfully decode thebroadcast transmission before receiving all of the repetitions). If thelow cost UE 120 is able to early decode the broadcast transmission, thelow cost UE 120 may indicate that the broadcast transmission was earlydecoded at 1004.

According to certain aspects, the determination of the bundling size forthe bundling paging message at 1006 may be determined (e.g., by the BS)based on the early decode indication from the low cost UE 120. Incertain aspects, the early decode indication may also be used to adjustthe bundling size. For example, as shown, based on the indication fromthe low cost UE 120, the BS 110 may transmit a bundled paging messagewith a bundling size of two.

According to certain aspects, the bundling size may be determined basedon measurement reports transmitted from the low cost UE. For example,the low cost UE may transmit one or more measurement reports to the BSduring a transition from RRC idle to RRC connected and the BS can useone or more values in the measurement report to determine the bundlingsize for the bundled paging message. The one or more values (e.g., RSRP,signal to noise ratio (SNR), etc.) may be indicative of the radioconditions between the low cost UE and the BS. Based on the one or morevalues in the measurement report(s), the BS can decide whether thebundling size for paging should be increased (e.g., if the measurementreport(s) indicate poor radio conditions, for example, below somethreshold) or decreased (e.g., if the measurement report(s) indicateradio conditions that are above some threshold).

According to certain aspects, the bundling size for paging may also bedetermined based on successful decoding of one or more bundled pagingmessages transmitted by the BS.

For example, in some cases, the BS may transmit bundled blank pagingmessages (e.g., paging messages meant for probing) to the low cost UE,where each of the bundled blank paging messages may be transmitted atbundle sizes that are known to the low cost UE. Referring again to FIG.10, for example, the bundled transmission may be a bundled blank pagingtransmission with a bundling size of six (known by the low cost UE 120)that is periodically transmitted by the BS 110. The low cost UE 120 maythen attempt to decode the bundled blank paging messages and may informthe BS 110 as to which paging messages were successful. For example, thelow cost UE 120 successfully decodes the paging message after twoattempts (i.e., the second out of six repetitions), the low cost UE 120may indicate to the BS 110 that the low cost UE 120 was able tosuccessfully decode the bundled paging message after two attempts. Ifthe low cost UE 120 was not able to successfully decode the bundledpaging message, the low cost UE 120 may indicate to the BS 110 that itwas not able to successfully decode the paging message. The BS 110 maythen use the indicated information to determine an updated bundling size(e.g., a decreased or increased bundling size relative to the previousbundling size) for the bundled paging message. For example, based on theindication from the low cost UE 120, the BS 110 may determine that thebundling size of two is sufficient for the bundled paging message.

Example Triggers for Determining Bundling Size for Paging

According to certain aspects, determination of the bundling size (e.g.,by the BS) can be triggered. In some cases, these triggers may allow thebundling size of the bundled paging message to be adapted/updated (asmentioned above) when one or more conditions are satisfied.

According to certain aspects, the determination of the bundling size maybe triggered each RRC connection attempt by the low cost UE. Forexample, every time the low cost UE makes a transition from RRC Idle toRRC Connected, the BS may determine a bundling size for the bundledpaging message to be transmitted to the low cost UE (e.g., radioconditions, measurement reports from the low cost UE, etc.). The BS cansignal an indication of the bundled paging size to the low cost UE.

According to certain aspects, the determination of the bundling size canalso be triggered during an initial attachment procedure or during atracking area update (TAU) by the low cost UE (e.g., which may occur aspart of a RRC or NAS procedure). According to certain aspects, thedetermination of bundling size can be triggered when the low cost UEselects or reselects a new cell. For example, in some cases, when thelow cost UE selects or moves to a new cell, the radio conditions betweenthe low cost UE and the new cell can change and the new cell may nothave knowledge of the updated conditions. To address this, techniquespresented herein may allow for the bundling size to be determined everytime the low cost UE selects or re-selects the new cell. In an exampleimplementation, when the low cost UE selects or re-selects the new cell,the low cost UE can initiate an RRC connection to trigger thedetermination of the new bundling size.

According to certain aspects, determination of bundling size for pagingcan be triggered by the low cost UE. For example, the low cost UE maydetermine that the current bundling size set by the BS is incorrect andshould be updated based one or more conditions. In some cases, the lowcost UE may determine that the current bundling size should be updated(e.g., trigger the determination) if the low cost UE has not received apaging message over a certain period of time (e.g., longer than athreshold period). In some cases, the low cost UE may determine that thecurrent bundling size should be updated if the low cost UE detects thatit is capable of acquiring a page with significantly less bundling thanthe bundling size used by the BS for a previously transmitted bundledpaging message (e.g., if the low cost UE early decodes in a similarmanner as shown in FIG. 10). In some cases, the low cost UE maydetermine that the current bundling size should be updated if the lowcost UE determines, based on one or more measurements (e.g., RSRP, SNR,etc.), that the radio conditions between the low cost UE and the BS havesignificantly changed.

If the low cost UE determines that the bundling size should be updated,the low cost UE can trigger the bundling size update by performing anRRC Connection procedure. According to certain aspects, the low cost UEcan also trigger the determination of the bundling size periodically,for example, by performing the RRC Connection procedure periodically toupdate the bundling size for paging.

According to certain aspects, the low cost UE may be informed about thedetermined bundling size for the paging message (e.g., implicitly orexplicitly by the BS). In one example, the low cost UE may be informedabout the determined bundling size semi-statically (e.g., before the lowcost UE returns to RRC Idle). In another example, the low cost UE may beinformed about the determined bundling size dynamically (e.g., as partof the paging message grant). According to certain aspects, the BS mayalso inform neighbor BSs/eNBs and/or the MME about the determinedbundling size for paging.

The various techniques described above may be combined in order todetermine a bundling size for the bundled paging message and/or todetermine when the determination of the bundling size is triggered. Forexample, in one case, the BS may receive a measurement report with oneor more measurements made by the low cost UE while the low cost UE is inRRC Connected mode and/or an early decoding indication from the low costUE based on early decoding of a bundled broadcast transmission by theBS. In another case, the determination of the bundling size may betriggered periodically by the low cost UE and/or every time the low costUE selects or reselects a new cell. In general, those of ordinary skillin the art will appreciate that other similar techniques describedherein may also be combined in order to enhance the paging proceduresfor low cost UEs.

Further, the various techniques described herein may be used to enhancepaging procedures for MTC and eMTC. Those of ordinary skill in the artwill appreciate that the techniques presented herein may also be appliedto other procedures in MTC and/or eMTC, such as random accessprocedures, transmission/reception of system information, etc.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover: a, b, c,a-b, a-c, b-c, and a-b-c, as well as any combination with multiples ofthe same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b,b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

As used herein, the term “identifying” encompasses a wide variety ofactions. For example, “identifying” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “identifying” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“identifying” may include resolving, selecting, choosing, establishingand the like.

In some cases, rather than actually communicating a frame, a device mayhave an interface to communicate a frame for transmission or reception.For example, a processor may output a frame, via a bus interface, to anRF front end for transmission. Similarly, rather than actually receivinga frame, a device may have an interface to obtain a frame received fromanother device. For example, a processor may obtain (or receive) aframe, via a bus interface, from an RF front end for transmission.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

The various operations of methods described above may be performed byany suitable means capable of performing the corresponding functions.One or more processors, circuits, or other devices may execute software.Software shall be construed broadly to mean instructions, instructionsets, code, code segments, program code, programs, subprograms, softwaremodules, applications, software applications, software packages,routines, subroutines, objects, executables, threads of execution,procedures, functions, etc., whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise. Themeans may include various hardware and/or software component(s) and/ormodule(s), including, but not limited to a circuit, an applicationspecific integrated circuit (ASIC), or processor. Generally, where thereare operations illustrated in Figures, those operations may be performedby any suitable corresponding counterpart means-plus-functioncomponents.

For example, means receiving and/or means for monitoring may include areceiver, such as receive processor 238, MIMO detector 236,demodulator(s) 232 a-232 t, and/or antenna(s) 234 a-234 t of the basestation 110 illustrated in FIG. 2 and/or MIMO detector 256, receiveprocessor 258, demodulator(s) 254 a-254 r, and/or antenna(s) 252 a-252 rof the user equipment 120 illustrated in FIG. 2. Means for determining,means monitoring, means for decoding, means for indicating, means forselecting, and/or means for performing, may include one or moreprocessors (or a processing system), such as controller/processor 240,scheduler 246, transmitter processor 220, receive processor 238, MIMOdetector 236, TX MIMO processor 230, and/or modulator(s)/demodulator(s)232 a-232 t of the base station 110 illustrates in FIG. 2, and/orcontroller/processor 280, receive processor 258, transmit processor 264,MIMO detector 256, TX MIMO processor 266, and/ormodulator(s)/demodulator(s) 254 a-254 r of the user equipment 120illustrated in FIG. 2. Means for signaling, means for transmitting,and/or means for indicating may include a transmitter, such as transmitprocessor 220, TX MIMO processor 230, modulator(s) 232 a-232 t, and/orantenna(s) 234 a-234 t of the base station 110 illustrated in FIG. 2,and/or transmit processor 264, TX MIMO processor 266, modulator(s) 254a-254 r, and/or antenna(s) 252 a-252 r of the user equipment 120illustrated in FIG. 2.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or combinations thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as hardware,software, or combinations thereof. To clearly illustrate thisinterchangeability of hardware and software, various illustrativecomponents, blocks, modules, circuits, and steps have been describedabove generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the disclosure herein may be implemented or performedwith a general-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thedisclosure herein may be embodied directly in hardware, in a softwaremodule executed by a processor, or in a combination thereof. A softwaremodule may reside in RAM memory, flash memory, ROM memory, EPROM memory,EEPROM memory, phase change memory, registers, hard disk, a removabledisk, a CD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal. In the alternative, theprocessor and the storage medium may reside as discrete components in auser terminal.

In one or more exemplary designs, the functions described may beimplemented in hardware, software, or combinations thereof. Ifimplemented in software, the functions may be stored on or transmittedover as one or more instructions or code on a computer-readable medium.Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage media may be anyavailable media that can be accessed by a general purpose or specialpurpose computer. By way of example, and not limitation, suchcomputer-readable media can comprise RAM, ROM, EEPROM, CD/DVD or otheroptical disk storage, magnetic disk storage or other magnetic storagedevices, or any other medium that can be used to carry or store desiredprogram code means in the form of instructions or data structures andthat can be accessed by a general-purpose or special-purpose computer,or a general-purpose or special-purpose processor. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer-readable media.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Thus, the disclosure is not intended to be limited tothe examples and designs described herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method for wireless communications by a userequipment (UE), comprising: determining one or more subframescorresponding to a paging occasion; monitoring the one or more subframesfor a transmission comprising control information for a bundled pagingmessage from a base station (BS), the bundled paging message associatedwith a bundling size; decoding the transmission comprising the controlinformation; determining the bundling size based at least in part on thecontrol information; determining at least one narrowband region, of aplurality of narrowband regions of a system bandwidth, in which the UEreceives the bundled paging message, wherein the determination of the atleast one narrowband region is based at least in part on the controlinformation; and receiving the bundled paging message, based at least inpart on the determined bundling size, in the determined at least onenarrowband region.
 2. The method of claim 1, wherein the bundling sizecorresponds to a number of times that a subframe of the bundled pagingmessage is repeated.
 3. The method of claim 1, wherein the determinationof the bundling size is based at least in part on the determined atleast one narrowband region.
 4. The method of claim 1, wherein thetransmission comprises a control channel transmission and is received ina second at least one narrowband region, of the plurality of narrowbandregions of the system bandwidth.
 5. The method of claim 1, wherein: theat least one narrowband region comprises a plurality of narrowbandregions; and the control information comprises an indication of at leasta first narrowband region of the at least one narrowband region.
 6. Themethod of claim 1, wherein the one or more subframes and the at leastone narrowband region are jointly determined.
 7. The method of claim 1,wherein the determination of the bundling size is based at least in parton signaling from the BS.
 8. The method of claim 1, wherein thedetermination of the bundling size is based at least in part on abundling size of a bundled random access channel (RACH) transmission,successfully decoded by the BS.
 9. The method of claim 1, furthercomprising: decoding a bundled broadcast transmission from the BS,wherein the bundling size is determined based at least in part on anumber of attempts to successfully decode the bundled broadcasttransmission from the BS.
 10. The method of claim 1, wherein thedetermination of the bundling size is based at least in part onmeasurements performed by the UE.
 11. The method of claim 10, furthercomprising: transmitting one or more measurement reports to the BS,wherein the bundling size is further determined based on the measurementreports.
 12. The method of claim 1, wherein the determination of the atleast one narrowband region is based at least in part on a defaultnarrowband region.
 13. The method of claim 1, wherein the determinationof the bundling size is triggered by a radio resource control (RRC)connection attempt by the UE.
 14. The method of claim 1, wherein thedetermination of the bundling size is triggered by an initial attachmentor a tracking area update by the UE.
 15. The method of claim 1, whereinthe determination of the bundling size is triggered by the UE selectingor reselecting a new cell.
 16. The method of claim 1, wherein thedetermination of the bundling size is triggered by an indication thatthe UE has not received a paging message over a period of time.
 17. Themethod of claim 1, wherein the determination of the bundling size istriggered by an indication that the UE is capable of acquiring a pagingmessage with a smaller bundling size than a bundling sized used by theBS for a previously transmitted bundled paging message.
 18. The methodof claim 1, wherein the determination of the bundling size is triggeredperiodically by the UE.
 19. The method of claim 1, further comprising:determining a connection mode of the UE, and wherein the determinationof the bundling size is based at least in part on the connection mode.20. The method of claim 19, wherein the connection mode comprises afirst connection mode that indicates that the UE is deployed in anon-mobility mode or a second connection mode that indicates that the UEis deployed in a mobility mode.
 21. The method of claim 19, wherein theconnection mode comprises a first connection mode that indicates thatthe UE is deployed in a normal power preference mode or a secondconnection mode that indicates that the UE is deployed in a low powerpreference mode.
 22. The method of claim 19, further comprising:selecting a second BS to communicate with; and performing a randomaccess procedure if the UE is deployed in a first connection mode, andthe determination of the bundling size is based at least in part on apre-configured or selected value if the UE is deployed in a secondconnection mode.
 23. A method for wireless communications by a basestation (BS), comprising: determining one or more subframescorresponding to a paging occasion; transmitting, over the one or moresubframes, a transmission comprising control information for a bundledpaging message to a user equipment (UE), the bundled paging messageassociated with a bundling size, wherein the bundling size is determinedby the UE based at least in part on the control information; determiningat least one narrowband region, of a plurality of narrowband regions ofa system bandwidth, in which the BS transmits the bundled paging messageto the UE, wherein the at least one narrowband region is determined bythe UE based at least in part on the control information; andtransmitting the bundled paging message to the UE, based at least inpart on the bundling size, in the at least one narrowband region. 24.The method of claim 23, further comprising: wherein the bundling sizecorresponds to a number of times that a subframe of the bundled pagingmessage is repeated.
 25. The method of claim 23, wherein thedetermination of the bundling size is based at least in part on thedetermined at least one narrowband region.
 26. The method of claim 23,wherein the transmission comprises a control channel transmission and istransmitted in a second at least one narrowband region, of the pluralityof narrowband regions of the system bandwidth.
 27. The method of claim23, further comprising signaling an indication of the at least onenarrowband region to the UE.
 28. The method of claim 27, wherein: the atleast one narrowband region comprises a plurality of narrowband regions;and the signaling comprises an indication of a first narrowband regionof the at least one narrowband region.
 29. The method of claim 23,wherein the one or more subframes and the at least one narrowband regionare jointly determined.
 30. The method of claim 23, wherein thedetermination of the bundling size is based at least in part on abundling size of a bundled random access channel (RACH) transmissionfrom the UE, successfully decoded by the BS.
 31. The method of claim 23,further comprising: transmitting a bundled broadcast transmission to theUE; receiving, from the UE, an indication of a number of attempts by theUE to successfully decode the bundled broadcast transmission; anddetermining the bundling size based at least in part on the indicatednumber of attempts.
 32. The method of claim 23, further comprising:receiving one or more measurement reports from the UE; and determiningthe bundling size based at least in part on the one or more measurementreports.
 33. The method of claim 23, wherein the determination of the atleast one narrowband region is based at least in part on a defaultnarrowband region.
 34. The method of claim 23, wherein the determinationof the bundling size is triggered by a radio resource control (RRC)connection attempt by the UE.
 35. The method of claim 23, wherein thedetermination of the bundling size is triggered by an initial attach ortracking area update by the UE.
 36. The method of claim 23, wherein thedetermination of the bundling size is triggered by the UE selecting orreselecting a new cell.
 37. The method of claim 23, wherein thedetermination of the bundling size is triggered by an indication thatthe UE has not received a paging message over a period of time.
 38. Themethod of claim 23, wherein the determination of the bundling size istriggered by an indication that the UE is capable of acquiring a pagingmessage with a smaller bundling size than a bundling size used by the BSfor a previously transmitted bundled paging message.
 39. The method ofclaim 23, wherein the determination of the bundling size is triggeredperiodically by the UE.
 40. The method of claim 23, wherein thedetermination of the bundling size is based at least in part ontransmitting bundled paging messages to the UE until a response from theUE is detected or until an indication is received from a network. 41.The method of claim 40, further comprising increasing the bundling sizefor each successive bundled paging message.
 42. An apparatus forwireless communications, comprising: means for determining one or moresubframes corresponding to a paging occasion; means for monitoring theone or more subframes for a transmission comprising control informationfor a bundled paging message from a base station (BS), the bundledpaging message associated with a bundling size; means for decoding thetransmission comprising the control information; means for determiningthe bundling size based at least in part on the control information;means for determining at least one narrowband region, of a plurality ofnarrowband regions of a system bandwidth, in which the apparatusreceives the bundled paging message, wherein the determination of the atleast one narrowband region is based at least in part on the controlinformation; and means for receiving the bundled paging message, basedat least in part on the determined bundling size, in the determined atleast one narrowband region.
 43. An apparatus for wirelesscommunications, comprising: means for determining one or more subframescorresponding to a paging occasion; means for transmitting, over the oneor more subframes, a transmission comprising control information for abundled paging message to a user equipment (UE), the bundled pagingmessage associated with a bundling size, wherein the bundling size isdetermined by the UE based at least part on the control information;means for determining at least one narrowband region, of a plurality ofnarrowband regions of a system bandwidth, in which the apparatustransmits the bundled paging message to the UE, wherein the at least onenarrowband region is determined by the UE based at least in part on thecontrol information; and means for transmitting the bundled pagingmessage to the UE, based at least in part on the bundling size, in theat least one narrowband region.
 44. An apparatus for wirelesscommunications, comprising: at least one processor; memory coupled withthe processor; and instructions stored in the memory and executable bythe at least one processor to cause the apparatus to: determine one ormore subframes corresponding to a paging occasion; monitor the one ormore subframes for a transmission comprising control information for abundled paging message from a base station (BS), the bundled pagingmessage associated with a bundling size; decode the transmissioncomprising the control information; determine the bundling size based atleast in part on the control information; determine at least onenarrowband region, of a plurality of narrowband regions of a systembandwidth, in which the apparatus receives the bundled paging message,wherein the determination of the at least one narrowband region is basedat least in part on the control information; and receive the bundledpaging message, based at least in part on the determined bundling size,in the determined at least one narrowband region.
 45. An apparatus forwireless communications, comprising: at least one processor; memorycoupled with the processor; and instructions stored in the memory andexecutable by the at least one processor to cause the apparatus to:determine one or more subframes corresponding to a paging occasion;transmit, over the one or more subframes, a transmission comprisingcontrol information for a bundled paging message to a user equipment(UE), the bundled paging message associated with a bundling size,wherein the bundling size is determined by the UE based at least in parton the control information; determine at least one narrowband region, ofa plurality of narrowband regions of a system bandwidth, in which theapparatus transmits the bundled paging message to the UE, wherein the atleast one narrowband region is determined by the UE based at least inpart on the control information; and transmit the bundled paging messageto the UE, based at least in part on the bundling size, in the at leastone narrowband region.
 46. A non-transitory computer readable mediumhaving code stored thereon, the code comprising instructions executableby at least one processor to: determine one or more subframescorresponding to a paging occasion; monitor the one or more subframesfor a transmission comprising control information for a bundled pagingmessage from a base station (BS), the bundled paging message associatedwith a bundling size; decode the transmission comprising the controlinformation; determine the bundling size based at least in part on thecontrol information; determine at least one narrowband region, of aplurality of narrowband regions of a system bandwidth, in which a userequipment (UE) receives the bundled paging message, wherein thedetermination of the at least one narrowband region is based at least inpart on the control information; and receive the bundled paging message,based at least in part on the determined bundling size, in thedetermined at least one narrowband region.
 47. A non-transitory computerreadable medium having code stored thereon, the code comprisinginstructions executable by at least one processor to: determine one ormore subframes corresponding to a paging occasion; transmit, over theone or more subframes, a transmission comprising control information fora bundled paging message to a user equipment (UE), the bundled pagingmessage associated with a bundling size, wherein the bundling size isdetermined by the UE based at least in part on the control information;determine at least one narrowband region, of a plurality of narrowbandregions of a system bandwidth, in which a base station (BS) transmitsthe bundled paging message to the UE, wherein the at least onenarrowband region is determined by the UE based at least in part on thecontrol information; and transmit the bundled paging message to the UE,based at least in part on the bundling size, in the at least onenarrowband region.